/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: BinOpExpr.java,v 1.2.4.1 2005/09/01 11:42:27 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodType;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
final class BinOpExpr extends Expression {

  public static final int PLUS = 0;
  public static final int MINUS = 1;
  public static final int TIMES = 2;
  public static final int DIV = 3;
  public static final int MOD = 4;

  private static final String[] Ops = {
      "+", "-", "*", "/", "%"
  };

  private int _op;
  private Expression _left, _right;

  public BinOpExpr(int op, Expression left, Expression right) {
    _op = op;
    (_left = left).setParent(this);
    (_right = right).setParent(this);
  }

  /**
   * Returns true if this expressions contains a call to position(). This is
   * needed for context changes in node steps containing multiple predicates.
   */
  public boolean hasPositionCall() {
    if (_left.hasPositionCall()) {
      return true;
    }
    if (_right.hasPositionCall()) {
      return true;
    }
    return false;
  }

  /**
   * Returns true if this expressions contains a call to last()
   */
  public boolean hasLastCall() {
    return (_left.hasLastCall() || _right.hasLastCall());
  }

  public void setParser(Parser parser) {
    super.setParser(parser);
    _left.setParser(parser);
    _right.setParser(parser);
  }

  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    final Type tleft = _left.typeCheck(stable);
    final Type tright = _right.typeCheck(stable);
    final MethodType ptype = lookupPrimop(stable, Ops[_op],
        new MethodType(Type.Void,
            tleft, tright));
    if (ptype != null) {
      final Type arg1 = (Type) ptype.argsType().elementAt(0);
      if (!arg1.identicalTo(tleft)) {
        _left = new CastExpr(_left, arg1);
      }
      final Type arg2 = (Type) ptype.argsType().elementAt(1);
      if (!arg2.identicalTo(tright)) {
        _right = new CastExpr(_right, arg1);
      }
      return _type = ptype.resultType();
    }
    throw new TypeCheckError(this);
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final InstructionList il = methodGen.getInstructionList();

    _left.translate(classGen, methodGen);
    _right.translate(classGen, methodGen);

    switch (_op) {
      case PLUS:
        il.append(_type.ADD());
        break;
      case MINUS:
        il.append(_type.SUB());
        break;
      case TIMES:
        il.append(_type.MUL());
        break;
      case DIV:
        il.append(_type.DIV());
        break;
      case MOD:
        il.append(_type.REM());
        break;
      default:
        ErrorMsg msg = new ErrorMsg(ErrorMsg.ILLEGAL_BINARY_OP_ERR, this);
        getParser().reportError(Constants.ERROR, msg);
    }
  }

  public String toString() {
    return Ops[_op] + '(' + _left + ", " + _right + ')';
  }
}
